Riyad as-Salihin, Book 18, Hadith 1706 (In-Book) ⓘ
Umm Salamah (May Allah be pleased with her) said: The Messenger of Allah said, "When anyone of you intends to sacrifice the animal and enter in the month of Dhul-Hijjah, he should not get his hair cut or nails pared till he has offered his sacrifice."[Muslim].
عن أم سلمة رضي الله عنها قالت قال رسول الله صلى الله عليه وسلم : "من كان له ذبح يذبحه، فإذا أهل هلال ذي الحجة، فلا يأخذن من شعره ولا من أظفاره شيئًا حتى يضحي" ((رواه مسلم)).